Our short intervals will be based on Veronique Billat's research, having Chris' work intervals all be at his vVoMax (the pace at which he first reaches his Vo2Max). Do as many 1:1 work pace:rest pace intervals as possible, and stop the workout when you can't maintain the split anymore.

Though she's primarily worked with runners, this interval protocol seems utterly ideal for working on a CII ... you'll never be in any doubt whether you're able to maintain the split or not.